I have setup a multiple data center configuration in Cassandra. My primary intention is to minimize the network traffic between DC1 and DC2. Want DC1 read requests be served with out reaching DC2 nodes. After going through documentation, i felt following setup would do.
Replica Placement Strategy: NetworkTopologyStrategy Replication Factor: 3 strategy_options: DC1 : 2 DC2 : 1 endpoint_snitch: org.apache.cassandra.locator.PropertyFileSnitch Read Consistency Level: LOCAL_QUORUM Write Consistency Level: LOCAL_QUORUM File: cassandra-topology.properties # Cassandra Node IP=Data Center:Rack 10.10.10.149=DC1:RAC1 10.10.10.150=DC1:RAC1 10.10.10.151=DC1:RAC1 10.20.10.153=DC2:RAC1 10.20.10.154=DC2:RAC1 # default for unknown nodes default=DC1:RAC1 Question I have: 1. Created a java program to test. It was querying with consistency level LOCAL_QUORUM on a DC1 node. Read count(Through cfstats) on the DC2 node showed read happened there too. Is it because of read correction?. Is there way to avoid doing read correction in DC2 nodes, when we query DC1 nodes. Thanks Selva
